A native of North Carolina, Mildred served as president of the Cooper Park Tenants Association for many years. A devout worshiper in the Free Gift Baptist Church, Mildred manifested her faith in the community by establishing youth and headstart programs, getting sidewalks and play areas built, and revitalizing the community center. She represented Copper Park Houses on GREC Community Coalition. Mildred was especially engaged in voter registration, going from building to building to encourage people to vote. She brought her 95-year-old mother who had never voted up from the South to show her the polls. Wearing three-inch high heels and a hat she inherited from Congresswomen Bella Abzug, Johnson was affectionately know as “the black Bella.” On election mornings she showed up around the pools at five and six a.m. with a bullhorn to proclaim that people should vote. In the same outfit, she coached the girls basketball team. Johnson was known as someone who would do anything for the neighborhood. Her concern encompassed the homeless, child care needs, and tenant concerns. She said people need a place to live—and worked to come up with solutions for the homeless. She would persuade people to come to meetings and drive them to conferences. A graduate of the Neighborhood Women College Program and the mother of three, Mildred was also involved in the Jackson Street School Settlement and engaged parents in the PTA.
The building at 302 Jackson St, Neighborhood Women Houses, is named after public housing leaders Mildred Johnson and Margaret Carnegie for bridging the differences between race, class and ethnicity in Brooklyn.